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

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

Obsessing about clients outside of work hours.

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

What do you think about a sister's love?

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.

Serious disappointment when the client cancels a session.

Milky Way galaxy might not collide with Andromeda after all - Ars Technica

General Introduction to Boundaries from Panahi Counseling:

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

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

How do flat earthers explain the Earth being stationary? Is this concept considered impossible?

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

Off the top of my ancient head:

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.

Has anyone ever read The Holy Bible completely through? If so, what was your overall impression of it?

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