Bro, next time she ask you whether u r coming over, just ask her anything else she need. If she need anything else, just buy for her. You can also tell her u saw some mouth-watering cakes, ask her whether she want some. With that, u can check out her fav flavour then start to work from there on the phone. After u bought the cake, she will definitely ask you to eat with her. The conversation will flow when two of you enjoyed the delicacy with light mood. The rest you know what to do from there!
