[M]y mother in law [F] seduced me while watching TV

So it was my MIL’s birthday (50) and we had drinks and so we decided to spend the night. My wife is an early sleeper and likes to sleep, so she went up in the guest room to sleep while I stayed downstairs with my MIL.
For a 50 yr old Ive always thought she was gorgeous. Chubby but really nice breasts and ass. She would often wear loose shirts and whenever she’d bend over I always got an eyeful.

So we’re watching tv, and she gets up, and tells me she’s going to get ready for bed and off she goes, leaving me to watch tv.

A couple minutes go by and I hear her coming back, she is in normal(ish) PJs, a pair of shorts with an undershirt and no bra, I immediately gaze down a little to see her nipples poking through. I start feeling blood rush down to my cock and it starts pulsing and rising, I tried to ignore it and continue watching tv, but I can’t stop thinking about her and what she’d look like without her clothes.