FIL feeding insecurities

I’m not sure whether this is an overreaction or not?

I’m currently 32 weeks pregnant with my first 🥳 and as proud and in awe of my body for this whole pregnancy, I do have some insecurities around my changing body and how my partner sees me.

My insecurity has been my own, and my partner has never made me feel anything but beautiful, and I’m glad I went through the pregnancy journey with him.

Yesterday my FIL made some comments that I thought were not really needed.

I’m not sure how to describe it but he sounded quite energetic/ enthusiastic/ encouraging/ something when he told my partner “JUST WAIT UNTIL YOU WALK THE BABY ON YOUR OWN! THE AMOUNT OF FEMALE ATTENTION YOU’LL GET IS PHENOMENAL!!!”

The look on my partner’s stepmothers face was horrified. I couldn’t quite read my partner but he changed the subject. When my FIL brought it up again, my partner looked at me and said “either I’ll run, so no one can speak to me, or I’ll take the cat, who will hiss, and leave the baby at home”.

Given my FIL separated from my MIL when my partner was about 5, remarried when my partner was 12, had a child with her, separated from her when that child was 3 months old, never paid child support for wither child, and is currently on his fourth marriage, he’s not someone I would idolise for relationships. But the comment didn’t land well with me given how vulnerable and insecure i currently feel.