He constantly says this, does it mean he's cheating?

My husband and I both say that to each other all the time. If he comes home from work and the back door is open because our toddler has been playing outside, he may say... you boyfriend forgot to shut his door on the way out. or somthing like that... and if he is late coming home I will say something like... Tell your girlfriend that next time she keeps you out this late... your not getting dinner for a month, so she needs to let you come home on time or she will be cooking for you! but we are both kidding! Neither of us are cheating and i am 1million % possitive!