Hey, Goku. How did you find out that Gohan was dating Future Trunks?

Gohan came t' me one day and told me he liked a guy. He said Videl was okay with that. But he didn't know how t' approach him or what t' do, so I gave him a few tips I learned from Vegeta. We practiced all night until Gohan had a better idea on how t' please a guy.
Thing is, when he got together with this guy, turns out they were both bottoms, see? So Gohan asked for my help again. I got him t' tell me who it was and, boy! Was I surprised t' find out it were my lover's kid, the one from the future!
Gettin' Vegeta t' agree with their relationship weren't that simple, but in the end, he relented and we both helped our kids with their problem. We had loads of fun together, just the four of us!