Most Helpful Guy
Nope. Especially if there's nothing sexual, you just have an online guy friend, fairly similar to a platonic guy friend in real life. Cheating would really only be if you started anything sexual or stuff.
Be very careful though. Anybody can be anybody online, and while it's quite possible to meet great people and make friends, always be wary of the fact that you can't really know for sure who's behind the keyboard. Hell my profile says 18-24, but for all anyone really knows I could be a 70 year old pedophilic grandma. Point is be friendly, but be wary, and don't be too free with personal information.
Hope that helped, feel free to comment/message if you need anything else