I am confused and seeking opinions.

Since my pregnancy my boyfriend barely touches me. I am overly horny and thinking dirty. His sister lives with us and has been a big help. She likes to rub my tummy and often massages me. It is getting warmer, I get bigger and I find myself getting thoughts of her. I find that I wear less clothing, trying to look sexy in front of her. I am loosing control and don't know what to do.

Help!