IDG Answers is a community of experts who are passionate about technology. Ask a question or answer one below.
First off, I’m not so sure you should use the term “friend” if they actually are spying on you. Apart from that, it is possible that you are being remotely monitored. On the other hand, malware/spyware that has nothing to do with this person could potentially be responsible for the issue you describe. I would be concerned about this, certainly. Here are some tips to help you determine whether you are being spied on and some steps to take to mitigate the risk.