Penn Zero from "Penn Zero: Part-Time Hero"
and from the same show, Penn and Sashi
Also, Randy Cunningham from "Randy Cunningham: 9th Grade Ninja"
From the same show, Randy and Theresa
And let us not forget about Kick Buttowski, from "Kick Buttowski: Suburban Daredevil" with this show's couple being Kick with Kendall Perkins
And let us not forget Finn from Adventure Time
I also think that Prohyas from Mighty Magiswords was straight
And as someone already mentioned, K.O. from "OK K.O.! Let's be Heroes" was a straight white boy, and his mom did get together with his boss, so that counts as a straight couple too
And while not the most macho, Dipper from Gravity Falls and Steven Universe were both white, straight, and male
Do I need to go on?