Why not have a session with a female tantra practitioner?
Firstly, there are benefits to having a session with a female, as that can aid sensuality and intimacy. Nevertheless, if the client is a heterosexual woman and she wants to improve her relationships with men, then having a session with a heterosexual man can be a greater catalyst for improving this dynamic.
For example, one of my clients had her boundaries violated regularly by her previous male partner. During our sessions, we focused on her communicating her no and I honouring it. As a result, she now feels that she has re-established her boundaries and that she is heard in her relationships. She believes that such an experience wouldn't have occurred as quickly with a woman practitioner.
Furthermore, sessions utilise sexual energy being generated and expanded, and if the client is heterosexual than such a connection is more likely to occur with a man (assuming he is also heterosexual).
A person's body is not a machine, with certain buttons being pressed to generate a response, rather the practitioner is a catalyst for channelling sexual energy; moving such energy into different regions of the client's body can provide a huge amount of healing and expansion.
Rather than the gender of the masseur/masseuse being important, the paramount question is 'does the person giving the massage have a clean, clear, feel to them?', as that's how the energy moves through without attachment.