I don't know how canon the Star Wars Tales comics are, but in one of the earlier ones, I think it was #9 (the one with Boba on the cover saying "Boba Fett, Intergalactic Man Of Mystery"), either way, I can't seem to find it now. Anyway, there was a Boba story in it where he goes hunting after a mysterious artifact, and runs into a femal bounty hunter (Syn, I think?) he seemed to have had past relations with. Later on, the artificat is revelaed to be a hologram projector, one showing Boba, Syn, and her holding a baby in her arms.
This story implies that Boba has had at least one child with someone out there. It is a big galaxy, and he is a pretty famous (infamous) hunter. I'm sure he's had some sort of relationship somewhere.
But this is Star Wars Tales, which also had a comic showing the R4 unit from the beginning of episode IV being "Skippy, the Jedi Droid!".
Abandon hope, all ye who enter