My son told me a huge secret now I’m screwed.

So riddle me this oh wise ones....My 25 year old son (only child) got married in June and found out he and his bride are pregnant in January. My son and I are very close and it helps that he can’t keep a secret to save his life. Within 30 mins of his wife peeing on the stick and her telling him they can’t tell a soul (even her mom which was a shocker) he ran out and hid in his garage to get a sneaky call in to share the news with me. I was thrilled...I mean crying and (literal) happy dance thrilled. I danced and cried the happiest of tears.I texted him today to ask him if he was ever going to admit to her that he couldn’t contain his excitement and had to spill it and his answer was NEVER!So here is the question....When she decides to tell me do I take an acting class and learn how to cry and dance on command so she gets the reaction she’s expecting? I’m scared that the kid is going to be like 8 years old when it slips out that I new all along and then she’s going to know my reaction was staged. Then I’m the MIL that not only lies but lied straight to her face. I’m also worried that I might not be a good enough actor and then she thinks I’m not happy for them.We have a wonderful relationship my DIL and I and I love her to pieces but I can’t rat on my son. He was so darn thrilled and just couldn’t contain his excitement. As far as he has told me I am the only one that knows anything at all and I’m not quite sure how I should handle it when the time comes. Suggestions? Thanks! via /r/Parenting https://ift.tt/31gFWi0