The general anwser is yes... probation has a lot of discretion in determining who you can relate with (drug dealers, gang memebers, etc.) ... but for a more specific anwser, you must look at the probation order signed by the judge at the time your boyfriend was sentenced. That will list the powers and authority that the probation officer has over your boyfriend.
This really seems to be more of a criminal law question than a family law one (I thought you were discussing Child Support Probation) when I saw the lead-in to the question. I'd suggest consulting with a criminal law attorney to see what your rights are.