Happy new month to boyfriend
That's so sweet! Here's a suggestion for a happy new month message for your boyfriend:
"Happy new month, love! May this month bring us even closer together and fill our days with laughter, adventure, and making memories. I'm so grateful to have you by my side. Here's to a fresh start and making this month one to remember!"
Or, if you want to keep it simple and short:
"Happy new month, babe! Wishing you a month filled with happiness, success, and lots of love"
Feel free to modify it to fit your personal style and relationship!