I'm About Losing The Man I Love And Being Pressured To Marry The One I Never Did

This is the story of a man who chose to be a gentleman and is on the verge of losing the woman he loves to another man.

Here's how the story went and still goes:
Caesar will be 30years old in May 2018. At about this same time in January last year, he ran into the woman who would cause him to love like he has never loved before. Her name is Sara.
Caesar and Sara both attended the same secondary school, but they never spoke back then. This was until they were added to a WhatsApp group made up of Alumni from their graduating set.

Caesar joined the group much later than Sara did and at first he didn't take notice of her much. Although he always saw comments made by Sara and found them intriguing, he didn't make any move towards her instead he focused on flirting with some of the other ladies in the group whom he used to speak to back in secondary school. This went on until Sara started developing a crush on the mysterious alumni who always seemed to have the right words to flirt with and she didn't hide it. She called out to him and being the attention lover Caesar is, he responded and asked her for a photo so he can know he was talking to.
Both of them developed a friendship that was mainly built on flirting and counter-flirting until they decided to chat each other up privately. Caesar told Sara outrightly that he liked her and wanted to have a relationship with her but she turned him down because according to her, she was already in a serious relationship.

Caesar was also in a relationship too, but once he and Sara started talking, she was all he could think about. This not withstanding, he wasn't ready to keep chasing a girl who said she was dating when he knew deep down that he was also dating even though she never asked.
He stopped chatting to her privately for about 5months and they only exchanged pleasantries during debates in the WhatsApp group. By July 2017, Caesar had started having issues in his relationship but he still didn't know how to go about telling Sara to just leave her boyfriend and be with him. Over the next few months, they would exchange private messages and act like friends. This was until November 2017 when Sara admitted to Caesar that her relationship was hitting the rocks .

She said her boyfriend had been talking about marriage since they started dating in January and was supposed to have rented a flat that would herald the beginning of their union only for her to find out that he renewed his rent for another year in his single room bachelor pad without informing her. Not to mention the fact that they were constantly fighting and arguing. On hearing all this, Caeser finally saw a way in and he took it without hesitation.
He started being persistent and made sure he let her know how he has felt for the past 11months.

Fast forward to January 2018, Sara has seriously fallen in love with Caesar even though she has not officially broken up with her boyfriend of one year who all of a sudden has started making plans to visit her family for the 'first knocking' (Introduction). The problem is, Sara is not interested in marrying him anymore as all she wants to do is to be with Caesar.
She invited Caeser over to her city and to her surprise he leaves a promise ring with her the night before he leaves and tells her that the ring is a promise from him showing that he is ready to take the plunge head deep and make her his wife. Meanwhile, her boyfriend of one year has not proposed or given her any ring. All he does is to say he is doing the introduction in February like he is suddenly in a hurry.

Now this is the reason why he is suddenly in a hurry. Caesar, Sara and her boyfriend are all Alumni in the same WhatsApp group. The boyfriend and Caesar are actually friends although not too close and Caeser only found out who this mystery boyfriend is after he visited Sara and she told him. She was told by the boyfriend to keep their relationship a secret from all old classmates before then but because he is suspecting that Sara and Caeser are seriously talking, he wants to rush and be the one who married her.

Sara's mum has given her an ultimatum to get married this year because she will also be 30 and according to her mum, she must get married this year. Caeser however may not be ready to marry her this year because he needs to sort out some things, which is why he gave her the promise ring (he actually attached the ring to her necklace so that she will always have it dangling on her neck and close to her heart).
They are both in love and have always been, and Sara blames Caeser for not being persistent last year. She blames him for letting her stay with her boyfriend till now even when she never really loved him.

Now her mum has told her that she must marry her boyfriend regardless of the love she feels for Caeser.
Both Caeser and Sara have both shed tears as they spoke tonight over the usual video call they share every night. Sara wants to be with Caeser for the rest of her life, but her mum is on her neck and this has left her broken because she does not feel any love for her boyfriend, she never did..she only dated him because she was single and he was the one who was persistent as at January last year while Caeser gave up too easy even when he was the one she really wanted.

Please you guys, ladies, ogas & madams, what do you think is the appropriate solution to this very delicate matter. I need your help and input please