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

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

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

Off the top of my ancient head:

What kind of pleasure do gay men get from being bottom? The idea is very appealing to me but in practice it's quite painful.

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

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.

General Introduction to Boundaries from Panahi Counseling:

What is your opinion on The Beatles' impact on modern popular music? Are there any other bands with similar impacts on their genre(s)? Why them and not others?

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

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

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

What is the one thing you don't understand that others do?

Obsessing about clients outside of work hours.

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

Serious disappointment when the client cancels a session.

What are the ten cars that make me no longer feel inferior?

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