Q. Can one have marital relations this year on the Shabbat Erev Shavuot, since it is during the three days before Kabalat Hatorah? Does it also apply to the second night of Shavuot?
A. Mishna Berura (494: 4,- 240: 7) writes that following Kabbala teachings one should avoid relations on the night of Shavuos, unless it is the immersion night He does not mention abstention during the three days before Shavuos, although at the giving of the Torah the nation did abstain on those days.
However, Mekor Chaim (ibid.), and Knessess Hagedola on the Tur (ibid.) do mention this minhag.
Kaf Hachaim (494: 13) maintains that the Arizal’s opinion is that it only applies to the night of Shavuos. Piskei Teshuvos (ibid. 8) quotes permitting opinions for the second night.
Horav Shlomo Miller’s Shlit’a opinion is to be lenient on both questions.
Rabbi A. Bartfeld as advised by Horav Shlomo Miller Shlit’a