All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
A mere kiss does not invalidate fasting if this does not lead to discharging Maniyy (sperm) or Mathy (preseminal fluid) because it is confirmed that ‘Aa’ishah said: “The Prophet used to kiss me while he was fasting and while I was fasting as well.” [Al-Bukhari, Muslim and Abu Daawood] However, if it leads to the discharge of Mathy, then the fasting is invalidated, similarly, if Mathy is discharged, the fasting becomes void according to the view of some jurists as we clarified in Fatwa 83622. For more benefit, please refer to Fataawa 104794 and 123504.
Hence, if the wife knows or predominantly thinks that when her husband kisses her or hugs her, this leads to the invalidation of her fast by discharging Maniyy or Mathy, then she should prevent him from doing so, and the husband is sinful for his act because he invalidates her obligatory fast the same way he invalidates it by having sexual intercourse with her.
Indeed, the scholars stated that “it is not permissible for her to answer her husband [when he calls her to bed] if she had already started making up the fasting with his permission, because when she starts the fast, the fasting becomes obligatory. Rather, it is an obligation which the husband had permitted, so he has no sound reason to invalidate it, and the husband is forbidden from calling his wife to bed while she is fasting an obligatory fast with his permission.”
Therefore, we advise your husband to avoid kissing you when you are fasting so that he would not cause the invalidation of your obligatory fasting, and he subsequently becomes sinful by doing so.
As regards your praying individually and not praying in congregation with your husband, then you are not sinful for this. A woman is not obliged to perform the prayer in congregation with her family, and she is not obliged to pray aloud in the prayers that should be performed loudly, because performing the prayer silently when the prayer is silent [i.e. Thuhr and ‘Asr], and performing the prayer loudly when the prayer is performed loudly [i.e. Fajr, Maghrib and ‘Isha] is a Sunnah according to the view of the majority of the scholars . Nevertheless, but you should not abandon this Sunnah for the reason that you mentioned in the question. For more benefit, please refer to Fataawa 92724 and 91135.
Allaah Knows best.