Decide Whether to Escalate a Simmering Conflict With a Colleague

Nothing has happened that you could point to in a meeting, just a pattern building up over weeks that is starting to grind. This helps you decide whether it is a formal conversation, a direct one to one, or genuinely small enough to let go, and gives you an opening line if a conversation is the answer.

There is an ongoing tension with a colleague that has not turned into a single clear incident, more a pattern building up over time: [describe the situation and pattern here]. Help me decide whether this needs raising formally with a manager, needs a direct one to one conversation with the colleague first, or is small enough to let go. Give me a clear recommendation with the main reason, and if a conversation is the right call, give me one opening line that names the pattern without sounding like an accusation.