Saying thanks

SAYING THANK YOU AFTER SEX.
In marriage,sex is not a REWARD, neither is it a BONUS OR SALARY. Rather it is the conjugal right and responsibility of both partners, because once you are married,your body automically belongs to your partner,according to:1corin7:3-4.
vs3 A husband should fulfill his obligation to his wife, and a wife should do the same for her husband.
vs4 A wife does not have authority over her own body, but her husband does. In the same way, a husband doesn’t have authority over his own body, but his wife does.

However,you can appreciate yourself after sex,if both of you enjoyed it. Hence,If you say thank you to each other after sex,it is out of respect and courtesy for each other.But there is no hard rule or law that says you must say" Thank you after Sex".