Me and DP have fucked financially up this month and finances are going to be very tight until DP gets paid on Wednesday. My brother was babysitting dd on Monday night and some cash must have fallen out of his jacket pocket as we found it in the morning and we definately know its not ours. To solve our problems DP wants me to delay telling him as its enough to get us through until next Wednesday, we would then return it fully to him. I don't feel very comfortable doing this though as my brother isn't exactly well off ( he's only 21 and works in a fairly low paid job) and it feels deceitful as we would be borrowing his money without his permission.