Most Helpful Guy
You will only be able to tell, if he doesn't meet the needs of fulfilling you back aka paying you back from what he has taken.
He said he will pay you back next week. Lets see if he does. If he doesn't and comes up with another excuse. Okay, I would make a note of it. But if it keeps happening and he's not making his own money to start contributing to the family that you want one day. Then you will know.
Right now, the signs are too early.
if this has been occurring for months on end, then clearly he is using u. Aka he's all sweet and sh*t but he's broke as a joke. If it has just started, you will have to see if it keeps up, or if it stops.
I would say the starbucks thing looks a little bit like a sign, but its not a big enough sign unless he's buying starbucks coffees like its unlimited daily on your card, and your refilling it every day or 2.
Pay closer attention to if this starts happening more recent. Wait out the week, see if he pays you back, or if he brings up the subject of paying you back. If he doesn't, I would take that card away from him, don't be mean about it, just tell him that you would like your starbucks card back, if he asks why, cause it keeps my finances straight aka you know how much you have all the time to spend on coffee.
Other then that, you will have to watch and see if he's actually true to his word, or if he's bullsh*tting. But right now its too early if this is the first case.