Matt Barnes former sister in law is telling him to squash the beef with Derek Fisher over her sister Gloria Govan.

TMZ Sports spoke with Laura Govan — whose sister is Gloria Govan, the mother of Barnes’ children who rebounded with Fisher after she and Matt broke up.

They asked Laura if she thinks Barnes will make good on his promise to fight Fisher again, a follow-up to their first clash back in October.

Laura’s response is measured and thoughtful, essentially saying Matt shouldn’t hold Fisher responsible for falling for Gloria because you never know where love is gonna come from.

She adds, “Things happen, you move on.”

Question is, do you think Matt will take the advice? Probably not.