Old boyfriends, street corners, and bar stools are everywhere in sobriety. As long as your loved one continues to prioritize their recovery, trust that they will walk on by.
If I had to characterize pot users in one sentence I would describe them as observers of their own life. This passivity cripples ambition and motivation. However, a strong relationship keeps the bridge open between you and your loved one, and this will be vital when they signal a desire to change.