What an amazing trip you're planning. Maybe your mother is a little jealous as well as over-protective. Unfortunately, some mothers do not recognise when to let go.

When you reach a certain age, she does not need to know everything. She is unfairly judging your relationship possibly against her own experiences and how things were done "in her day".

A few years ago, to celebrate a significant birthday, I suggested to my mother and aunt (her sister) that we went on a cruise together. She went along with the idea then suddenly said she couldn't bear the thought of sharing a cabin with me. So I withdrew the suggestion and booked 10 days in the Caribbean on my own. She then spent the time up to departure telling me I shouldn't do it.

If you are happy to do this trip with your boyfriend, regardless of your living arrangements, then go ahead. Enjoy the experience and maybe send her cards or photos from the places you visit.