Capea is a fascinating word in this context, as it's a colloquial term that can mean "to get away with something" or "to manage to do something," often implying a bit of stealth or cleverness.
In the song, the singer repeatedly asks "a ver si capea," which translates to "let's see if she gets away with it" or "let's see if she manages it." He's hoping his girlfriend can sneak away from her mom to spend time with him, adding a playful and slightly mischievous tone to the lyrics. It's a great example of informal Spanish that adds character to the song.
La Zenda Norteña's "Haber Si Capea" is a fun, lighthearted tune about a guy trying to get some alone time with his girlfriend. He's planning a secret rendezvous, hoping to find a spot where her mom won't see them. He sings, "voy a buscar un rincón donde no nos vea su mami a ver a ver si capea" [I'm going to look for a corner where her mommy doesn't see us, to see if she'll 'capea' (go along with it)].
But what if she doesn't "capea"? He's got a backup plan, and it's pretty funny! If she doesn't go along with his plan for a secret date, he declares, "pues me tendré que casar con todos las de su casa voy a tener que arreglar voy a hablar con su papá y su mamá" [well, I'll have to marry everyone in her house, I'll have to fix things, I'm going to talk to her dad and her mom]. It's a humorous way of saying he's serious about her and will do whatever it takes, even if it means getting the whole family involved! He just can't wait any longer for this "linda morena" [beautiful brunette].