The last guy I seriously dated had two kids, with primary custody.
We saw each other pretty regularly, but whenever the kids were with their mom for a weekend he was ungodly levels of horny. Like, "back away and let me BREATHE" levels.
Reading the posts from all the dads in here is giving me greater understanding of him. Lol
As a married dad, I can't speak for all dads and I especially cannot speak for single dads. However, I have found that parenthood has turned sexy time into the most high-stakes game of hide and seek ever. It kind of spiced things up for us. "OK that one's asleep and the other is watching Paw Patrol... GO GO GO". Also I find I get so much attention from women when I'm out with one or both of my kids. Mostly friendly, quite a bit of it flirty. I think it does a lot for my confidence, and I bring that energy home.
I had a boys camping trip a couple of months ago and we were talking about sex frequency over beers around the fire. We are all happily married, aged 31 to 40, one had a pregnant wife, the rest all have 1 or 2 kids, and the range was interesting. Every day or two, down to once every two weeks. There definitely was a correlation between frequency and contentment. Every second or third day (so about 3 times a week) seems to be the sweet spot for me, but those days where you can fit in two in one day? God damn, those days make life worth living.