He is texting you because he thinks he can renew your interest by getting in touch while with his partner. He is testing you. He wants to have his cake and eat it too. If you answer you tell him that you will settle for someone with a partner. He gets to boost his ego and you have to settle. He is disrespecting his partner and any participation by you will be welcome. He probably has a list of excuses for why the relationship with her is not what he bargained for. This is the way it goes. He may want to get you to have pity for him and then he has the best of both worlds. He is doing this so that he can stroke his ego and he ends up with the benefit of two relationships. He may be right that it isn't working but that doesn't mean he should involve you. He probably hasn't made up his mind or doesn't want to but he still is not honoring his relationship and her trust. This isn't a sign of good character. You have to draw the line and say I won't tolerate this.
His reasons are what they are. I think he is trying to develop two relationships. Don't allow that to happen. What is happening to her now could happen to you later. Be mindful of that.
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