How to get rid of group joining statuses at the bottom of the activity page

[Trixx]

So I was attempting to report this group because the image that they used contained nudity. I was using my mobile (windows phone, not iOS). When I was about to choose the reason I accidentally hit the join group button in the background. I was embarrassed by this, partly because I knew it would show up at the bottom of the activity page, and because I do not pleasure myself to pictures of furries. I quickly left the group. But sure enough at the bottom of the activity page it said I joined the group. Is there any way to get rid of this?