Bhrgu went to officiate at Daksha Yagna and couldn't do anything to Virabhadra (Siva's assistant) when he pulled out the mustache and beard of Bhrgu
https://www.wisdomlib.org/hinduism/book/the-bhagavata-purana/d/doc1127089.html
- Glorious Vīrabhadra pulled out mustaches and the beard of Bhṛgu, while he was offering the oblations with sruva (a ladle) in his hand, as he had laughed derisively in the assembly showing his beard (when Dakṣa insulted Śiva).
How credible is the story of Bhrgu's alleged, extravagant curse on Siva, a curse he allegedly uttered out of sight of Siva?
aren't curses and blessing uttered face-to-face?
https://www.wisdomlib.org/hinduism/book/the-padma-purana/d/doc365840.html
26-27. Thus addressed, the best sage, along with Vāmadeva, quickly went to Kailāsa where the bull-bannered (god) lived. Having gone near the door of the house of the magnanimous Śaṅkara and seeing very fierce Nandin with a spear in his hand, he said (to him):
28-34. “I, the brāhmaṇa Bhṛgu, have come to see Hara, the best god. Quickly announce me (i.e. my arrival) to the magnanimous Śaṅkara.” Hearing the words of him, Nandin, the lord of (Śiva’s) attendants spoke harsh words to the great sage of an unlimited splendour: “The lord is not in the vicinity. Śaṅkara is sporting with goddess (Pārvatī). O best sage, go back if you desire to live.” Thus repudiated by him the (sage) of a great penance remained there, at the door of the great lord, for many days. “Since he, arrogant due to the company of a woman, thinks lightly of me, he shall have the form of clitoris. Approached (i.e. overcome) by vice he slights me, a brāhmaṇa! Reduced to an impious state, he will not be adored by brāhmaṇas. Therefore, all the food, water, flowers and oblations offered to him will undoubtedly be useless.”
35-40. The very lustrous one, having thus cursed Śaṃkara honoured by the world, said to the very fierce attendant, Nan-din, holding a spear, O king: “May Śiva’s devotees, having ash, phallus and bones be impious and out of the Vedic fold.” The sage, having thus cursed Rudra, Tripura’s killer, went to Brahmā’s world, respected by all people
(1) If Nandi never informed Siva of Bhrgu's visit it was Nandi who deserved to be cursed.
(2) Pronouncing a curse on Siva, not to Siva's face but to Nandi seems to be just venting, not an effective curse.
Gods voluntarily accept curses, if they are proportionate - but this alleged curse by Bhrgu for an alleged minor slight bears all the hallmarks of an interpolation by a Siva-hater, especially since Siva is equated with Brahman elsewhere in the Padma Purana.
