Are you that bad looking or just look dumb? Otherwise why would this client say anything?!

If it's a young person you're caring for that you're referring to as your "client," I will say young people can have a very weird perspective of your position. This occurrence honestly doesn't surprise me. It's little to nothing personal. They either have an expectation that, if they view you as older and further along in life, you are already married, or that, having a job of your sort, that sort of job-holder wouldn't be in a boyfriend-girlfriend relationship. It's hard to explain. Sometimes part of a job's description is that you're going to be viewed a certain way simply because of the position that you hold. Kids are idiots. I wouldn't be surprised if even a parent makes this remark; some jobs are very stereotyped. Don't worry, and don't take it harshly. I wouldn't even take it personally. Even if a kid did mean it in a personal manner, as I said, kids are idiots.

can you imagine the what client's reaction will be when you tell them it's not really butter?

At least they didn't say "B*tch, please,who you think you foolin'?"

Maybe your client is just in Denial because they want you for themselves.