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

Off the top of my ancient head:

Serious disappointment when the client cancels a session.

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

Is it okay if I sleep with my brother without my husband knowing?

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

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:

Why does my private parts itch so much during certain periods?

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

Obsessing about clients outside of work hours.

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

What would have happened if Shin was a good movie instead of a bad one?

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

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

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

Why after 50 years of being straight do I constantly desire to suck cock?

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