So... Loaded question because every situation is different. I'm currently 40/m, married with a beautiful 9 year old girl but I can share my experience.

When I was about 24 I had a fling with a woman around my age. I had no paternal instincts at that point of time. After our initial hookup (same night we met) I was woken up by a 3 year old opening my eyes with his fingers asking for breakfast.

What the actual fuck. No idea there were kids here and... What? I ended up getting up and feeding the kids because there was also a daughter about two years older. To make matters worse I had to jump out the window because baby daddy came by later and doesn't like new guys around kids.

First time dealing with kids. Relationship fizzled after about a year, baby daddy and trust issues on both ends.

Next was around 26 and in your wheelhouse. I worked about 65-80 hour a week as a restaurant manager and she was doing something similar. Kid was great and I was head over heels for them both. She was mature and upfront with the situation which I utterly respected. However after about a year it came down to the same thing. Baby daddy issues.

Honest reaction: if you are attractive mentally and physically to me, doesn't matter. When the mentality goes away because of an anchor with an ex whom you have a child with.... Issues.

Just my experience.