What are some signs that a therapist may have poor boundaries with their clients?

Session-expressed curiosities about client details not relevant to the therapy.

Off the top of my ancient head:

Routinely going over the time limit with certain patients, compromising the time for the next client.

Delta Force selection is originally based on SAS selection, so why is there no brutal jungle phase for Delta Force? It seems like it's based only on the Brecon Beacons section.

Sense of competition with persons who are important in the client’s life.

General Introduction to Boundaries from Panahi Counseling:

Serious disappointment when the client cancels a session.

What is the difference between the terms "Millennials" and "kids"?

Failing to mention the client in supervision/consultation, out of fear the supervisor/consultant will advise return to ordinary healthy boundaries.

Obsessing about clients outside of work hours.

Struggling with fantasies of deeper connections with clients, whether sexual or parental or other intense or intimate relationships beyond psychotherapy.

Why The Simpsons stopped producing Maude Flanders episodes?

Disclosing feelings, fantasies, and experiences to the client in ways not related to the work the client is engaged in.

Frequent phoning or texting of clients to “check up on them and make sure they’re OK.”

These items can happen fleetingly, briefly, in any therapy, but if they’re frequent, it’s definitely time for the therapist to get some good, solid supervision/consultation.

What does it feel like wearing tights?

Eager anticipation (or anxious anticipation) of the next session in ways that distract.