It is in Scene Five that Tom finally announces to Amanda that he has done what she asked him to do, and invited one of his work colleagues round to his home. This, of course, sends Amanda into a flurry of excitement and anticipation as she begins to interrogate Tom about Jim and who he is, his position, his salary and his background. This in turn makes Tom annoyed at having even asked him in the first place, and he shows great irony in some of his responses to Amanda. He does admit that he did not mention Laura to Jim:
One little warning. He doesn't know about Laura. I didn't let on that we had dark ulterior motives. I just said, why don't you come nad have dinner with us? He said okay and that was the whole conversation.
Notice his sarcasm in "dark ulterior motives." Tom thus has complied with his mother's wishes, but his concern for Laura shows that he perhaps did this grudgingly and without really believing that this might be best for Laura.