Is OTHER wrong in the post ? POST : &amp;#x200B;

My friend (15) and I (17) were approached by a guy in his early 20s. Let's call him J. He thought we were college students and from a very good art college in our state (RISD). We told him we were just high schoolers. We basically begin to talk to him every morning at the bus station waiting for our bus while he waited for his to go to work. One day, he had this idea of collaborating with us making up a design for a sweater, because he told us his younger brother had a clothing line and would hook us up with his younger brother to get a contract and money from him. The thing is, J had no way for us to contact, no phone,  no social media or anything. It's pretty weird because he always talks about wanting to get into RISD when he doesn't have anything out there to promote himself. My friend and I worked on an idea, and I drew it on a canvas he brought us. J drew his part and wanted us to paint over it. We're both sucky at painting btw, and his part was...kind of bad. One thing we had caught on before our painting assignment from him was how he said he was going to put it on his portfolio for RISD and credit us. He stated before that he'd always wanted to go to RISD and pursue a career in graphics design.  Okay, we only agreed to do the sweater designs to hopefully get some cash, not this. 

&amp;#x200B;

After that we had a feeling he might have been using us for his portfolio and found it a little uncomfortable. We decided to ignore him for 3 weeks (we had a 2 week break and another one before break). We're still trying to decide if we should just give him the canvas and never talk to him again, or not. I mean it's been 3 weeks. We don't know what to say to him, and we feel pretty bad that he won't make it into his dream school but uncomfortable for using our idea for that. Are we the assholes in this situation?   


TL;DR: Older guy offers to help my friend and I with setting us up with his younger brother for a sweater design and possible contract, uses our design idea and combines his to just declare at the end that he wants it for his portfolio. Ignores him for 3 weeks. 