If its borderlands... I might be able to play co-op with you (keep in mind, because I only recently got the game, I never bothered to play co-op in fear of sucking so much)
Borderlands isn't TOO hard in co-op, but it raises the difficulty of enemy's a bit for each person in your team, and the money/item drop rate goes up quite a bit. But it seems like i might do a couple rounds of LoL first then borderlands